The environmental group Waterkeeper Alliance provided ABC11 photographs that show pumping equipment and hoses leading to a nearby canal and drain pipe.
DENR said the agency is "working with Duke" to figure out what those pumps were doing and whether they were permitted.
Environmentalists said they're concerned Duke was trying to get water out of the pools more quickly than the law allows. That would constitute illegal dumping. DENR officials have been quoted as saying "While routine maintenance is allowed under the permit, discharge of untreated wastewater could be a violation."
ABC11 has asked Duke to comment on the pumping since last week, and has received no response. Over the weekend, Duke officials told the New York Times that said the pumping was intended to lower the water level in the ponds, which contain a slurry of coal ash with toxic heavy metals, as part of a "routine maintenance" program and was allowed under the site's antipollution permit.
Duke's coal ash ponds have been under intense scrutiny since a pipe in a pond at Duke's Eden plant - next to the Dan River - collapsed February 2, dumping millions of gallons of water laden with toxic ash downstream.
Ash was spread as far as 70 miles down the river.
Late Monday evening, Duke Energy had this response:
- Crews were using a temporary pumping system to lower water levels in two basins at the Cape Fear plant to perform upcoming maintenance.
- We had identified, through routine inspections, that maintenance was needed on the "risers" – the vertical pipes that transfer basin water to the discharge system. Our permit authorizes this type of maintenance specifically under the condition that we meet permit limits. The water was being pumped to the existing, permitted outfalls. Discharges from those permitted outfalls are monitored, and continued to be, throughout this process.
- This work began last fall, and the company notified DENR in August before it began.